CONTINUOUS-WAVE PARAMETRIC OSCILLATION IN LITHIUM TRIBORATE

We demonstrate a continuous-wave optical parametric oscillator that uses lithium triborate as the nonlinear material in a temperature-tuned noncritical phase-matched type I geometry. Pumped at 514.5 nm, the triply resonant oscillator has a threshold of 50 mW. We obtain peak output powers of 90 mW corresponding to a 10% external conversion efficiency and measure a tuning range of 0.966 to 1.105 mum, limited by the bandwidth of the mirrors. Operating the optical parametric oscillator both at and away from degeneracy, we observe rapid changes in output power as a function of cavity length owing to competition between signal and idler mode pairs.